1. Field of the Invention
The present invention relates to a fluid power generator, as well as to a motor device having a function of electric power regeneration.
2. Description of the Related Art
For reduction of carbon dioxide, power generations by utilizing natural energies, such as wind power generation, hydraulic power generation, and photovoltaic power generation, have been attracting a great deal of attention. Enhancement of the efficiency of such natural energy power generations is of great importance to solve the environmental problems.
A fluid power generator may be constructed, for example, with application of a brushless motor structure. One example of the brushless motor structure is disclosed in JP 2001-298982A.
One typical example of the fluid power generator is a wind power generator. A prior art structure of the wind power generator adopts a heavy weight of blades, in order to prevent rotation of the blades from being stopped by a decrease of wind force and to prevent a decrease in power generation efficiency with a variation in rotation speed caused by the varying wind force. The heavy blades enhance the inertial force of rotation and keep the rotation of the generator.
This prior art structure, however, undesirably expands the dimensions of the whole wind power generator in order to support the heavy blades and requires the enhanced intensity of a support member for supporting the heavy blades in the wind power generator. Such drawbacks are not characteristic of the wind power generator but are commonly found in various fluid power generators. Efficient regeneration of electric power in a motor drive is also highly demanded.